Methods of manufacturing paint roller covers from a tubular fabric sleeve

ABSTRACT

A method of manufacturing paint roller covers is disclosed in which the paint roller covers are manufactured from a seamless, tubular fabric sleeve knitted in a pile side-in manner and including at least one of a backing material and a pile made, at least in part, from a low melt fiber or yarn component. The seamless, tubular fabric sleeve is inverted to a pile side-out configuration, placed onto a cylindrical member, and heat is applied to cause the low melt fiber or yarn in the backing and/or looped ends of the pile to be activated and to closely conform to the size of the cylindrical member, thereby causing the melted and fused together, re-hardened low melt component of the seamless, tubular fabric sleeve to remain in a cylindrical configuration, forming an integrally formed core member.

IDENTIFICATION OF RELATED APPLICATION

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 12/132,774, filed on Jun. 4, 2008, now U.S. Pat.No. 8,221,578, entitled “Methods of Manufacturing Paint Roller CoversFrom a Tubular Fabric Sleeve,” which is in turn a continuation-in-partof U.S. patent application Ser. No. 12/100,050, filed on Apr. 9, 2008,entitled “Methods of Manufacturing Paint Roller Covers From a TubularFabric Sleeve,” which is in turn a continuation-in-part of U.S. patentapplication Ser. No. 12/015,612, filed on Jan. 17, 2008, now U.S. Pat.No. 7,905,980, entitled “Methods of Manufacturing Paint Roller CoversFrom a Tubular Fabric Sleeve,” each of which patent applications areassigned to the assignee of the present invention, and each of whichpatent applications are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to the manufacture of paintroller covers, and more particularly to methods of manufacturing paintroller covers from a seamless, tubular fabric sleeve knitted in a pileside-in manner and having a backing constructed at least in part from alow melt material, and optionally, having a pile constructed at least inpart from a low melt material.

The two inventions which have had the greatest impact on paintapplication are the invention of the paint roller in the 1930's and thedevelopment of water-based paint in the late 1940's. While water-basedpaints are easy to mix, apply, and clean up, there is little doubt thatthe paint roller has been the greatest single time saving factor in thepaint application process, allowing large surfaces to be painted with auniform coat of paint quickly and easily. Typically, paint rollers arecomprised of two components, namely a handle assembly and a paint rollercover for installation onto the handle assembly.

The handle assembly consists of a grip member having a generallyL-shaped metal frame extending therefrom, with the free end of the metalframe having a rotatable support for a paint roller cover mountedthereon. The paint roller cover consists of a thin, hollow cylindricalcore which fits upon the rotatable support of the handle, with a plushpile fabric being secured to the outer diameter of the paint rollercover. The core may be made of either cardboard or plastic material,with which material is used for the core generally being determinedbased upon the selling price of the paint roller cover. The pile fabricis traditionally applied as a strip which is helically wound onto theouter surface of the core with adjacent windings of the fabric stripbeing located close adjacent each other to provide the appearance of asingle continuous pile fabric covering on the core.

Typically, the pile fabric is a dense knitted pile fabric, which may beknitted from natural fibers such as wool or mohair, synthetic fiberssuch as polyester, acrylic, nylon, or rayon, polypropylene or from ablend of natural and synthetic fibers. The knitting is typicallyperformed on a circular sliver knitting machine, which produces atubular knitted backing or base material with a pile knit on the insideof the tubular segments which are approximately fifty-eight inches (1473millimeters) in circumference by thirty to fifty yards (27.43 meters to45.728 meters) long (depending on fabric weight).

Generally, sliver knitting is a knitting process which locks individualpile fibers directly into a lightweight knit backing or base material ina manner wherein the pile fibers extend from one side of the knit basematerial. The knit base material itself is made from yarn, which may beknitted in a single jersey circular knitting process on a circularknitting machine, with closely packed U-shaped tufts of the fibers beingknitted into the knit base material which anchors them in the completedpile fabric. The free ends of the fibers extend from one side of theknit base material to provide a deep pile face. The knit base materialis typically made of synthetic yarns, with the pile being made of adesired natural or synthetic fiber, or a blend of different fibers.

Such fabrics are illustrated, for example, in U.S. Pat. No. 1,791,741,to Moore, U.S. Pat. No. 2,737,702, to Schmidt et al., U.S. Pat. No.3,226,952, to Cassady, U.S. Pat. No. 3,853,680, to Daniel, U.S. Pat. No.3,894,409, to Clingan et al., U.S. Pat. No. 4,236,286, to Abler et al.,U.S. Pat. No. 4,513,042, to Lumb, and U.S. Pat. No. 6,766,668, toSinykin, all of which patents are hereby incorporated herein byreference. Sliver knit high pile fabrics have been widely used for manyyears in the manufacture of imitation fur fabrics, and also have founduse, for example, as linings for overcoats and footwear, as coveringsfor stuffed toys and floors, in applications in pet beds, case liners,boot and slipper liners, medical pads, and blankets, and, of course, ascoverings for paint roller covers.

The components of the knitted fabric are a yarn, which is used to knitthe fabric's knit base material, and fibers which are supplied in a“sliver” rope, which consists of fibers which are all longitudinallyoriented in a rope which is typically less than three inches (76millimeters) in diameter. The fibers are loose fibers of either a singletype or a uniform blend of multiple types of fibers. The fiber mix willdetermine the performance, density, texture, weight, patterning, andcolor of the finished pile fabric.

The fibers are typically blown together in an air chamber to blend them,and then are carded in carding machines that “comb” the fibers to alignthem in parallel with each other. The fibers are then gathered into asoft, thick rope which is called “sliver” (which is the derivation forthe term “sliver knit”) or “roving.” The yarn and the sliver aresupplied to the circular knitting machine, which typically has eighteenheads and produces a tubular knit pile fabric which is approximatelyfifty-eight inches (1473 millimeters) in circumference. (Thus, when thetubular knit pile fabric is slit longitudinally, the fabric isapproximately fifty-eight inches (1473 millimeters) wide.)

Such knitting machines are well known in the art, and are illustrated inU.S. Pat. No. 3,894,407, to Clingan et al., U.S. Pat. No. 3,896,637, toThore, U.S. Pat. Nos. 4,532,780 and 4,592,213, both to Tilson et al.,U.S. Pat. Nos. 5,431,029, 5,546,768, 5,577,402, 5,685,176, and6,016,670, all to Kukrau et al., and U.S. Pat. No. 6,151,920, toSchindler et al., all of which patents are hereby incorporated herein byreference. Examples of commercial versions of such knitting machines arethe Model SK-18 Sliver Knitter and the Model SK-18J Sliver Knitter whichare available from Mayer Industries, Inc. of Orangeburg, S.C.

The first commercial circular sliver knitting machine had seven heads,and commercially-available circular knitting machines today have betweenseven and eighteen heads. Eighteen head knitting machines have upwardsof one thousand needles, and produce tubular knitted segments that areapproximately nineteen inches (483 millimeters) in diameter (fifty-eightinches (1473 millimeters) in circumference). All of these circularsliver knitting machines produce tubular knitted pile fabric segmentshaving the pile located on the inside. Such circular sliver knittingmachines are incapable of either producing tubular knitted pile fabricsegments having the pile on the outside or small diameter tubularknitted pile fabric segments.

Following the manufacture of the tubular knitted pile segments on acircular sliver knitting machine, the tubular knitted pile segments areslit longitudinally to produce extended knitted pile segments of fabricwhich are typically fifty-eight inches (1473 millimeters) wide by thirtyto fifty yards (27.43 meters to 45.728 meters) long. These extendedknitted pile segments of fabric are then tensioned longitudinally andtransversely, stretched to a sixty inch (1524 millimeter) width orgreater to guarantee the proper number of two and seven-eighth inch (73millimeter) strips, and back coated (on the non-pile side of the knitbase material) with a stabilized coating composition such as a clearacrylic polymer. The coating composition which is coated onto thenon-pile side of the knit base material is then processed, typically byheat, to stabilize the coated, extended knitted pile segment. Theheating operation dries and bonds the coating composition to the knitbase material, producing a fabric which is essentially lint-free.

The coated, extended knitted pile segment can then be subjected to ashearing operation to achieve a uniform pile length, with the shearedfibers being removed by vacuum, electrostatically, or by any other knownremoval technique. The pile density, the nap length, and the stiffnessof the fibers are varied based upon custom specifications and theparticular characteristics of the paint roller cover that are desired.

The sheared, coated, extended knitted pile segment is then slit into aplurality of two and seven-eighths inch (73 millimeter) wide knittedpile fabric strips, of which there are typically twenty for a sixty inch(1524 millimeter) wide fabric segment. During this slitting operation,the strips may be vacuumed to remove stray fibers and lint. The knittedpile fabric strips are rolled onto a core to produce twenty rolls ofknitted pile fabric strips, each of which is thirty to fifty yards long.These rolls of knitted pile fabric strips may then be shipped to a paintroller cover manufacturer. Alternately, a plurality of standard lengthsof the fabric may be seamed together to produce an extended lengthfabric strip which may be helically wound in consecutive rows upon acore as taught in U.S. Pat. Nos. 6,502,779, 6,685,121, 6,902,131,6,918,552, and 6,929,203, all to Jelinek et al., all of which patentsare hereby incorporated herein by reference.

Both the standard length rolls of knitted pile fabric strips and therolls of extended length knitted pile fabric strips have substantialmaterial costs and labor costs that are incurred in the manufacturingprocess after the circular knitting process. The material costs includethe cost of the coating material, losses due to fly (fly are extrafibers that come loose from the knitted pile fabric), losses during thecutting of the sixty inch (1524 millimeter) wide fabric segment intotwenty knitted pile fabric strips, and seam losses throughout theoperation. The labor costs include the costs to perform the coatingprocess, the brushing, the second pass shearing, and all of thefinishing steps within the traditional sliver knit operation includingslitting and continuously coiling the fabric slits.

Paint roller covers are manufactured by using a hollow cylindrical coremade of cardboard or thermoplastic material which has the knitted pilefabric strip helically wound around the core. During the manufacture ofpaint roller covers, the knitted pile fabric strips are secured to thecore either by using adhesive or epoxy, or by thermally bonding theknitted pile fabric strip in place on a thermoplastic core. For examplesof these manufacturing processes see U.S. Pat. No. 4,692,975, to Garcia(the “'975 Patent”), U.S. Pat. No. 5,572,790, to Sekar (the “'790Patent”), and U.S. Pat. No. 6,159,320, to Tams et al. (the “'320Patent”), each of which are hereby incorporated by reference.

The '975 Patent uses a core that is cut from preformed thermoplastic(e.g., polypropylene) tubular stock. The core is mounted on a rotatingspindle, and a movable carriage mounted at an angle to the spindle feedsa continuous strip of knitted pile fabric onto the core, with thecarriage moving parallel to the spindle in timed relation to itsrotation so that the knitted pile fabric strip is wound on the plasticcore in a tight helix. Also mounted to the movable carriage is a heatsource for heat softening the thermoplastic core just in advance of thepoint where the knitted pile fabric strip is applied to thethermoplastic core, such that the knitted pile fabric is heat bonded tothe thermoplastic core as it is wound thereupon. The bond formed betweenthe knitted pile fabric and the thermoplastic core is a strong one notsubject to separation from exposure to paint solvents.

The '790 Patent uses a core that is formed from a strip (or multiplestrips) of thermoplastic material that is (are) helically wound about astationary mandrel. Alternately, the core may be formed by applyingliquefied thermoplastic material to a drive belt which transfers thethermoplastic material to the mandrel. A layer of adhesive is thenapplied to the outer surface of the core, and the knitted pile fabricstrip is applied to the core by helically winding the knitted pilefabric strip onto the core. Alternately, the paint roller cover mayinstead be made by bonding, in a single step, a knitted pile fabricstrip to a wound strip of thermoplastic material that is wrapped aboutthe mandrel.

The '320 Patent extrudes a cylindrical plastic core through a rotatingextruder head that is cooled, with the outer surface of the core thenbeing plasma treated. The knitted pile fabric strip is secured onto theplasma treated outer surface of the core by extruding thin films offirst and second epoxy resin subcomponents onto the outer surface of thecore as it is extruded, cooled, and plasma treated in a continuousprocess.

Other variations are also known, particularly in technologies relatingto manufacturing pile fabric suitable for use on paint roller covers.For example, instead of using knitted pile fabric, woven pile fabric canbe substituted. Woven pile fabric consists of three yarns—a knit basematerial or warp yarn, a filling or weft yarn, and a pile yarn. Thethreads of warp yarn are held taut and in a parallel array on a loom,and the threads of weft yarn are woven across the threads of warp yarnin an over/under sequence orthogonal to the threads of warp yarn, withthreads of pile yarn being woven into the weave of warp and weft yarnssuch that the threads of pile yarn extend essentially perpendicularlyfrom one side of the fabric. Such woven pile fabric may be processed ina manner similar to that described above with regard to the processingof knitted pile segments of fabric to produce strips of woven pilefabric that can be helically wound onto paint roller cover cores.

However, all paint roller covers manufactured using the methodsdescribed above have a seam. As the strips of fabric are helically woundaround the cores, the fabric strips wrap contiguously around the core,thereby creating a helical seam that is located throughout the cover.The seam inevitably produces a less than optimal paint roller coversince a seam can interfere with the uniform application of paint fromthe paint roller cover. The helical winding process of manufacturing apaint roller cover requires careful attention to contiguous winding.Errors resulting in overlapped fabric or gaps in the contiguous windingprocess often occur, resulting in increased scrap or marketing poorquality covers. Such seams have the potential, particularly with shortnap paint roller covers, to produce a seam mark or stippling effect onthe surface being painted, particularly if the paint being appliedcombines with the seams to produce a more pronounced defectivecharacteristic in the surface being painted.

An examination of prior technology in the paint roller cover artsreveals that this problem has been recognized in the past, with severalsolutions that have been proposed to deal with the challenge presentedby the presence of seams in paint roller covers. The first of these,U.S. Pat. No. 2,600,955, to Barnes et al., which patent is herebyincorporated herein by reference, discloses a paint roller cover madefrom a segment of canvas tubing that has yarn loops sewn therethrough,with the ends of the loops on the outside of the segment of the canvastubing being cut. This approach is certainly far too expensive torepresent a viable solution, and would not compare well to currentlycommercially available paint roller covers in the quality of the paintcoat that could be applied.

Another approach is shown in U.S. Pat. Nos. 2,704,877 and2,752,953, bothto Arnold Schmidt, which patents are hereby incorporated herein byreference, which patents are related and disclose a tubular knitted pilefabric that is stated to have been manufactured on an apparatusdisclosed in U.S. Pat. No. 1,849,466, to Moore, which patent is herebyincorporated herein by reference. The apparatus disclosed in Moore,which is hand operated, was stated in several related patents toSannipoli et al. (U.S. Pat. Nos. 2,920,372, 2,944,588, and3,010,867,which patents are hereby incorporated herein by reference) to be capableof manufacturing a seamless tubular knitted sleeve in which the pile islocated on the interior of the sleeve, thereby requiring that the sleevebe inverted prior to mounting it on a core to form a paint roller cover.As such, the apparatus disclosed in Moore is incapable of manufacturinga knitted sleeve in which the pile is located on the exterior of thesleeve.

The Sannipoli et al. patents inverted the tubular knitted sleeve bypositioning it within a hollow tube and pulling one end of the tubularknitted sleeve around the end of the tube and pushing successiveportions of the tubular knitted sleeve along the outside of the tube.The Arnold Schmidt '877 patent (which failed to disclose how it invertedthe knitted sleeve with the pile on the interior thereof) disclosed amachine for treating and shearing inverted tubular knitted sleeves, andthe Arnold Schmidt '953 Patent disclosed using the inverted, treated,and sheared tubular knitted sleeves by stretching them and pulling themover a tube or shell to form a paint roller.

The problem that has prevented the inventions of the Arnold Schmidtpatents and the Sannipoli et al. patents from being either practical orcommercially successful is that the process of inverting a tubularknitted sleeve having the pile on the interior of the sleeve inevitablydamages the fabric of the tubular knitted sleeve. When the fabric isinverted, the material of the fabric is deformed due to stretching thatoccurs during the process of inverting the tubular knitted sleeve. Thisdeformation tends to increase the diameter of the tubular knittedsleeve, thus requiring it to be stretched lengthwise to restore it toits former diameter. Not only is this process difficult and expensive,but it also results in variable density of the fabric as well asintroducing the prospect of adhesive or thermoplastic bleed-throughwithin the stitches. Such problems will result in unacceptable productquality in paint roller covers made from this type of fabric.

It has been determined that the inverting approach taught by theSannipoli et al. patents and useable by the Arnold Schmidt patents hasthree drawbacks that make it impracticable. The first drawback of theinverting method is that it requires a high degree of manual operationin that it requires cutting of the tubular knitted sleeves to size andplacement of the tubular knitted sleeves into the tubes of the invertingmachine. The second drawback of the Sannipoli et al. method is that onlyrelatively short length tubular knitted sleeves representing a singlepaint roller cover (typically nine inches (229 millimeters)) can beprocessed at a time, which makes the method inherently unsuitable formass production.

The third, and by far the most serious, drawback of the Sannipoli et al.method is that the process of inverting the tubular knitted sleevesinevitably results in stretching the tubular knitted sleeves so thatthey will not snugly fit on the paint roller cover cores, potentiallycreating creases in a high percentage of them when they are adhesivelysecured to the paint roller cover cores. This results in an unacceptablyhigh percentage of them being defective and necessitating them beingscrapped, resulting in an unacceptably high scrap cost. Predictably, theinventions taught in the Sannipoli et al. patents and the Arnold Schmidtpatents have never found commercial acceptance due to these seriousdisadvantages.

It would therefore be desirable to provide a tubular knitted fabricmanufactured on a conventional knitting machine, such as one of theabove-described apparatus and methods, that is knitted pile side-in, butthat can be inverted to a pile side-out configuration and be utilized inthe manufacture paint roller covers. More specifically, there is a needto manufacture paint roller covers from a tubular knitted fabricmanufactured in a pile side-in manner that does not result in a paintroller cover having wrinkles and/or a deformed pile outer surface. It ishighly desirable that the manufacturing method results in an acceptablepile which extends from an acceptably rigid core that can be installedon and used with any conventional paint roller frame.

The method used to manufacture a paint roller cover from the tubularpile fabric must result in a construction which is both durable and longlasting, and which, when accomplished, should yield a paint roller coverof superior quality. In order to enhance the market appeal of the methodof the present invention, it should also minimize the cost ofmanufacture of paint roller covers when compared to conventional methodsof manufacturing paint roller covers to thereby afford it the broadestpossible market. Finally, it is also desirable that all of the aforesaidadvantages and aspirations of the paint roller cover manufacturingmethod of the present invention be achieved without incurring anysubstantial relative disadvantage.

SUMMARY OF THE INVENTION

The disadvantages and limitations of the background art discussed aboveare overcome by the present invention. With this invention, a method ofmanufacturing paint roller covers from a tubular knitted fabric that isknitted pile side-in is provided. The tubular knitted fabric segmentincludes a knit base material knitted from a backing yarn and aninwardly facing pile comprising sliver fibers, cut yarn pile segments ora combination thereof. At least one of the backing yarn and the pile ismade, at least in part, from a low melt material and/or a special kindof yarn made from bicomponent fibers.

Bicomponent fibers are comprised of two polymers that have differentchemical and/or physical properties and which are extruded from the sameextrusion device with both polymers contained within the same fiber.Most commercially available bicomponent fibers are configured with theirtwo constituent polymers arranged either in a sheath-core arrangement, aside-by-side arrangement (also referred to as a bilateral arrangement),an eccentric sheath-core arrangement (which is a geometric variation ofsheath-core construction), a matrix-fibril arrangement (also referred toas an inlands-in-the-sea arrangement), and a segmented pie arrangement(also referred to as a citrus arrangement). The bicomponent fibers usedby the present invention are “low melt” bicomponent thermal binderfibers that utilize polymer combinations such as a sheath-corearrangement in which the core material has a relatively higher meltingpoint than the sheath material. These alternatives are examples, sincemany other low-melt configurations can also be manufactured. (It will beappreciated that the low melt yarn can be made from more than twopolymer constituents, as is well known to those skilled in the art, andas described below.)

Such low melt bicomponent fibers are available from Fiber InnovationTechnology, Inc. of Johnson City, Tenn., and from Kuraray Co., Ltd, ofTokyo, Japan. Typical higher melt (which may be used in a core)materials are polyester (most preferred) or polypropylene, and typicalsheath materials are polyethylene terephthalate (PET, most preferred),polyethylene, and copolyester. Typical lower melt (which may be used ina sheath) melting points of bicomponent fibers may be betweenapproximately 121 and 260 degrees Centigrade (between 250 and 500degrees Fahrenheit).

The backing yarn and/or the pile fiber/yarn used by the presentinvention may thus be made of such low melt bicomponent fibers; suchyarn shall be referred to herein as “bicomponent fiber yarn.”Alternately, the backing yarn and/or pile fiber may instead be abicomponent yarn which is made of two different types of fibers or yarns(yarns can be manufactured using different types of fibers or ring spunwith two different types of yarn), one of which fiber or yarn types hasa lower melting point than the other fiber or yarn type; this yarn shallbe referred to herein as “bicomponent yarn.” The bicomponent fiber yarnand the bicomponent yarn shall collectively be referred to herein as“low melt yarns.”

Consistent with the broader aspects of the present invention, the term“low melt yarn” can encompass yarns including at least one low meltfilament or strand, as described above, and also including a pluralityof additional high melt or non-low melt filaments or strands that arecombined together by methods well known to those skilled in the art. Theadditional high melt/non-low melt filaments or strands may be comprisedof any suitable natural or synthetic fiber suitable for combination withthe low melt fiber or strand. Suitable materials include but are notlimited to nylon, rayon, polypropylene, polyester, polyester-cottonblends, cotton, wool and acrylic. Other materials may be used so long asthey are compatible with the selected low melt yarn and the finalapplication of the tubular knitted pile fabric segment. In this way, thepresent invention is not limited to low melt yarns having only twocomponents and includes low melt yarns having multiple strandcomponents.

It will be appreciated that the ratio of low melt component to high meltcomponent used in a particular low melt yarn encompassed by the presentinvention, will vary depending on the particular end use application ofthe tubular knitted pile fabric segment. Where a more rigid integralcore is to be formed, a low melt yarn having a low melt fiber or strandcomposition that is substantially equal to or greater than the high meltcomponent composition can be used. For applications where the integralcore of the tubular knitted pile fabric segment may be furtherreinforced, a low melt fiber or strand composition that is less than thehigh melt component composition can be used.

The linear mass density of the backing yarn, the pile fibers and/or cutyarn segments used by the present invention may vary betweenapproximately 150 denier and approximately 1500 denier, with a preferredlinear mass density being between approximately 560 denier andapproximately 1200 denier. It will be understood, however, that thelinear mass density of each fiber or strand of the bicomponent ormulti-component low melt yarn will be determined by the specificfiber/strand selected, and is a matter of design choice, depending atleast in part on the knitting equipment utilized and the end useapplication of the tubular knitted pile fabric segment.

The use of low melt yarns for the base of a sliver knit fabric isdiscussed in U.S. Pat. No. 6,766,668, to Sinykin, which patent isassigned to the assignee of the present invention, and which patent ishereby incorporated herein by reference in its entirety. This patentused heat to activate the low melt material in the base, heating thesliver knit fabric to a temperature for a sufficient period of time topermit the low melt material to melt about the central and/orintermediate portions of the sliver fibers. The sliver knit fabric wasthen cooled so that the low melt material returned to a hardened stateand captured a portion of the sliver fibers to lock them to the base ofthe fabric. This represents a substantially different use of bicomponentfibers than that of the present invention, as will become evident below.

The low melt yarn backing and/or the low melt sliver fibers, cut pileyarn segments or a combination of both sliver fibers and cut pile yarnsegments are knitted in a pile side-in manner into the tubular knittedpile fabric segment by methods known to those skilled in the art.Non-limiting examples of such manufacturing methods and apparatus aredisclosed in the above-incorporated by reference U.S. Pat. Nos.2,704,877 and2,752,953, both to Arnold Schmidt, U.S. Pat. No. 1,849,466,to Moore, and/or U.S. Pat. Nos. 2,920,372, 2,944,588, and3,010,867, toSannipoli et al., each of which discloses a seamless tubular knittedsleeve manufactured so that the pile is located on the interior of thesleeve.

The pile side-in tubular knitted fabric of the present invention is cutinto the desired length or size and then inverted for further processingto form the tubular knitted pile fabric segment having an integrallyformed paint roller core of the present invention.

The tubular knitted pile fabric is then placed onto a cylindricalmandrel which is the approximate size of the inner diameter of a paintroller cover (typically approximately one and one-half inches (38millimeters)). The cylindrical mandrel may be made, for example, ofsteel (which may optionally have a non-stick coating such as PTFE orsilicone) and has a heating mechanism contained inside which is capableof rapidly heating the outside of the mandrel to a desired temperature.The cylindrical mandrel is heated to the desired temperature, which isless than about 343 degrees Centigrade (less than 650 degreesFahrenheit) or any temperature suitable for activating the low meltyarn. One temperature range that may be acceptable is betweenapproximately 121 and 218 degrees Centigrade (between 250 and 425degrees Fahrenheit). This temperature is sufficient to melt the lowermelting point component of the low melt yarn used in the backing or baseand/or the looped ends of any pile fibers also including a low meltcomponent. The temperature is maintained for a period of betweenapproximately five seconds and approximately ninety seconds, preferablyapproximately five to approximately sixty seconds.

The melted lower melting point component of the low melt yarn used inthe backing or base of the tubular knitted pile fabric and/or the meltedlooped ends of the pile fibers flow into the cylindrical form of theoutside of the cylindrical mandrel. The melted lower melting pointcomponent also flows between the high melt backing loops and the centraland/or intermediate portions of the sliver fibers or the loops of thecut pile yarn segments, and locks the sliver fibers or cut pile yarnsegments into the tubular knitted pile fabric. This greatly reduces thedegree of shedding of pile fibers from the tubular knitted pile fabric.It also converts the backing from a fabric into a unitary cylindricalassembly which, when cooled, will become substantially rigid. Themandrel is then cooled or allowed to cool, after which the rigid,cylindrical pile fabric assembly is removed from the mandrel.

In a first alternate embodiment, one or more layers of a dry adhesivefilm may be first wound on a non-stick mandrel, following which thetubular knitted pile fabric segment is placed over the dry adhesivefilm. The mandrel is then heated to cause the dry adhesive film and thelower melting point component of the low melt yarn used in the backingor base of the tubular knitted pile fabric to melt together with theadhesive bonding material to create an even more rigid cylindricalassembly having a pile surface.

In a second alternate embodiment, a layer of spray adhesive is sprayedon to the cooled, substantially rigid integral core formed by there-hardened low melt yarn to create an enhanced rigid cylindricalassembly having a pile surface.

The rigid, cylindrical pile fabric assembly is finished by combing andshearing the pile fabric to the desired length. The edges of theunfinished paint roller covers are beveled, and any loose sliver fibersare then vacuumed off. The finishing of the rigid, cylindrical pilefabric assembly may be performed using the MBK Maschinenbau GmbH paintroller cover finishing machine, an Edward Jackson (Engineer) Limitedfinishing machine, or other equipment custom built by individual paintroller cover manufacturers.

It may therefore be seen that the present invention teaches a method bywhich a paint roller cover may be manufactured from tubular knitted pilefabric using a base or backing and pile fibers comprising, at least inpart, a low melt yarn.

The paint roller cover manufacturing method of the present inventionresults in an acceptable pile which extends from an acceptably rigidcore which can be installed on and used with any conventional paintroller frame, or on a frame uniquely designed for the paint rollerutilizing the new core design. The paint roller cover manufacturingmethod of the present invention facilitates either the manufacture of apaint roller cover of a desired finished length, or the manufacture ofan extended length segment from which segments of any desired size canbe cut for finishing as paint roller covers, thereby facilitating themass manufacture of paint roller covers. The paint roller covermanufacturing methods of the present invention can use tubular sliverknitted pile fabric, tubular knitted yarn cut pile fabric, tubularknitted fabric including both sliver knitted pile and cut pile yarn, aswell as a number of different backing materials.

The paint roller cover manufacturing method of the present inventionresults in a construction which is both durable and long lasting, andyields a paint roller cover of superior quality. The paint roller covermanufacturing method of the present invention also reduces the cost ofmanufacturing paint roller covers when compared to conventional methodsof manufacturing paint roller covers by manufacturing paint rollerswithout using a core member, thereby affording it the broadest possiblemarket. Finally, all of the aforesaid advantages and aspirations of thepaint roller cover manufacturing method of the present invention areachieved without incurring any substantial relative disadvantage.

DESCRIPTION OF THE DRAWINGS

These and other advantages of the present invention are best understoodwith reference to the drawings, in which:

FIG. 1 is an isometric view of a segment of tubular paint roller fabricmade according to the teachings of the present invention, with the pileextending inwardly, showing a tubular knit base having pile fibersextending inwardly therefrom;

FIG. 2 is cross sectional view of the segment of pile side-in tubularknitted paint roller fabric illustrated in FIG. 1, showing the inner andouter diameters of the tubular fabric;

FIG. 3 is a schematic view of a portion of a first embodiment of atubular paint roller fabric knitted in a pile side-in manner, asillustrated in FIGS. 1 and 2, shown from the inside thereof, showing theknitting pattern of the base yarn and the placement of pile fibers fromthe sliver into the knit base;

FIG. 4 is a schematic view of a portion of a second embodiment of atubular paint roller fabric knitted in a pile side-in manner, asillustrated in FIGS. 1 and 2, shown from the inside thereof, showing theknitting pattern of the base yarn and the placement of cut pile yarnsegments into the knit base;

FIG. 5 is a schematic view of a portion of a third embodiment of atubular paint roller fabric knitted in a pile side-in manner, asillustrated in FIGS. 1 and 2, shown from the inside thereof, showing theknitting pattern of the base yarn and the placement of tufts of sliverfibers and cut pile yarn segments into the knit base;

FIG. 6 is a cross sectional view of a sheath-core bicomponent fiberhaving a core made of a material that has a higher melting point thanthe material that its sheath is made of;

FIG. 7 is a cross sectional view of a side-by-side bicomponent fibershowing opposite sides that are respectively made of materials havingdifferent melting points;

FIG. 8 is a cross sectional view of an eccentric sheath-core bicomponentfiber having a core made of a material that has a higher melting pointthan the material that its sheath;

FIG. 9 is a cross sectional view of a matrix-fibril bicomponent fiberhaving a plurality of segments made of a material that has a highermelting point located within a sheath that is made of a lower meltingpoint material;

FIG. 10 is a cross sectional view of a segmented pie bicomponent fiberhaving alternating wedges made of materials having different meltingpoints;

FIG. 11 is a cross sectional view of a bicomponent yarn showing twodifferent types of fibers, one of which fiber types has a lower meltingpoint than the other fiber type;

FIG. 12 is a longitudinal cross sectional view of a mandrel heatingassembly having a cartridge heater and a thermocouple located inside acylindrical mandrel;

FIG. 13 is a lateral cross sectional view of the mandrel heatingassembly shown in FIG. 12;

FIG. 14 is a schematic depiction of a controller that uses the signalfrom the thermocouple illustrated in FIG. 12 to control the cartridgeheater also illustrated in FIG. 12;

FIG. 15 is an isometric view of the segment of tubular paint rollerfabric illustrated in FIGS. 1 through 5, showing the pile side-in fabricsegment being inverted from a pile side-in configuration to a pileside-out configuration;

FIG. 16 is an isometric view of the segment of tubular paint rollerfabric illustrated in FIG. 15, showing the inverted tubular paint rollerfabric segment in a pile side-out configuration;

FIG. 17 is cross sectional view of the segment of the inverted tubularpaint roller fabric segment illustrated in FIG. 16, taken along the line17-17 therein, showing the distorted and stretched segment havinginconsistent/non-uniform inner and outer diameters;

FIG. 18 is a schematic isometric depiction showing an end of an invertedtubular knitted pile fabric about to be slid onto an outer non-sticksurface of a hollow cylindrical aluminum heating tube;

FIG. 19 is a schematic isometric depiction of the tubular knitted pilefabric illustrated in FIG. 18, with the tubular knitted pile fabricbeing partially slid onto the outer non-stick surface of the aluminumheating tube;

FIG. 20 is a schematic isometric depiction of the tubular knitted pilefabric illustrated in FIGS. 18 and 19, with the tubular knitted pilefabric now located upon the outer non-stick surface of the aluminumheating tube;

FIG. 21 is a schematic isometric depiction of the tubular knitted pilefabric and the outer non-stick surface of the aluminum heating tubeillustrated in FIGS. 18 through 20 about to be slid onto the mandrelheating assembly;

FIG. 22 is a schematic isometric depiction of the tubular knitted pilefabric and the outer non-stick surface of the aluminum heating tubeillustrated in FIGS. 18 through 21 located upon the mandrel heatingassembly illustrated in FIG. 17 and being heated;

FIG. 23 is a schematic isometric depiction of the tubular knitted pilefabric that was heated on the aluminum heating tube and the mandrelheating assembly illustrated in FIGS. 21 and 22 with the backing fusedinto a rigid cylindrical configuration;

FIG. 24 is a schematic isometric depiction showing a wide segment of dryadhesive film beginning to be wound around the outer non-stick surfaceof the aluminum heating tube;

FIG. 25 is a schematic isometric depiction showing one or more windingsof dry adhesive film on the aluminum heating tube shown in FIG. 24;

FIG. 26 is a schematic isometric depiction showing an end of a tubularknitted pile fabric about to be slid onto the one or more windings ofdry adhesive film on the aluminum heating tube shown in FIG. 25;

FIG. 27 is a schematic isometric depiction of the tubular knitted pilefabric, the one or more windings of dry adhesive film, and the aluminumheating tube illustrated in FIG. 26 about to be slid onto the mandrelheating assembly;

FIG. 28 is a schematic isometric depiction of the tubular knitted pilefabric, the one or more windings of dry adhesive film, and the aluminumheating tube illustrated in FIGS. 26 and 27 located upon the mandrelheating assembly illustrated in FIG. 27 and being heated; and

FIG. 29 is a flow diagram showing the manufacturing of a paint rollercover that is made according to the teachings of the present invention,with a number of the steps being those illustrated in FIGS. 1 through28.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The paint roller cover manufacturing methods of the present inventionuses a tubular paint roller fabric that may be a tubular knit basehaving sliver pile fibers extending inwardly therefrom, a tubular knitbase having cut pile yarn segments extending inwardly therefrom or atubular knit base having a combination of sliver pile fibers and cutpile yarn segments extending inwardly therefrom. At least one of thetubular knit base and the sliver fibers/cut yarn pile is made, at leastin part, of a low melt yarn. As illustrated in the following Figures andas described in more detail herein, the methods of the present inventioncan be used with good effect on tubular knit fabrics knitted in a pileside-in manner and having any type of pile fibers, as will be known tothose skilled in the art, provided that the knit base and/or the pilefibers comprise, at least in part, a low melt yarn or fiber component.

Referring first to FIGS. 1 and 2, an exemplary tubular knit segment 30that may be continuously knitted in an extended length is shown in apile side-in configuration. Such an extended length tubular fabricsegment 30 can be manufactured by any method known to those skilled inthe art, including but not limited to those manufactured as described indetail in the above-incorporated by reference U.S. Pat. Nos. 2,704,877and2,752,953, both to Arnold Schmidt, U.S. Pat. No. 1,849,466, to Moore,and/or U.S. Pat. Nos. 2,920,372, 2,944,588, and3,010,867, to Sannipoliet al., each of which discloses a seamless tubular knitted sleevemanufactured so that the pile is located on the interior of the sleeve.

The pile side-in tubular knit segment 30 includes a knit backing or basematerial indicated generally at 32 having pile fibers indicatedgenerally at 34 extending from the knit base material 32 on the interiorsurface of the tubular knit segment 30. The knit base material 32 cancomprise, at least in part, a low melt yarn that will be discussedbelow. In certain other embodiments of the present invention, the pilefibers 34 can also comprise, at least in part, low melt yarn. As will beappreciated by those skilled in the art, at least one of the knit basematerial 32 and the pile fibers 34 include a low melt yarn. The pileside-in tubular knit segment 30 includes a top edge 33, a bottom edge 35and a length 36 extending therebetween. It will be appreciated that thepile side-in tubular knit segment 30 may be knitted in as long a lengthas desired, notwithstanding that FIG. 1 only shows a relatively shortpiece of the pile side-in tubular knit segment 30.

As best illustrated in FIG. 2, the pile side-in tubular knit segment 30has an essentially circular cross section and is formed to have an innerdiameter 37 and an outer diameter 38. As will be appreciated, the pileside-in tubular knit segment 30 is manufactured to have a substantiallyuniform inner diameter 37 and outer diameter 38 along its entire length36. The pile side-in tubular knit segment 30 is manufactured to have aninner diameter that is preferably sized so that when it is inverted, itwill be of a size that substantially corresponds to a typical paintroller cover. As such, the inner diameter 37 can be about one andone-half inches (38 millimeters), although depending on the type of enduse paint roller application, the pile side-in tubular knit segment 30can be manufactured to have a smaller or larger inner diameter.

It will be understood that FIGS. 1 and 2 are representative of a typicalconstruction for a pile side-in tubular knit fabric that can be used inthe methods and paint roller covers of the present invention. Examplesof variations of the knit base 32 and pile fiber 34 constructions foruse in the pile side-in tubular knit segment 30 are described in moredetail with respect to FIGS. 3 through 5.

Referring next to FIG. 3, a segment of the pile side-in tubular sliverknit segment 30 is shown in schematic form from the inside thereof toillustrate the knit of the knit base material 32, and the manner in thepile fibers 34 are woven into the knit base material 32. Those skilledin the art will at once realize that while the tufts of the pile fibers34 shown in FIG. 3 include only a few fibers each for added clarity andunderstanding of the construction of the pile fabric 30, tufts of thepile fibers 34 in the pile side-in tubular knit segment 30 will actuallyinclude sufficient pile fibers 34 to make a pile that is sufficientlydense for the intended use of the tubular sliver knit segment 30 in themanufacture of a paint roller cover.

The foundation of the pile side-in tubular sliver knit segment 30 is theknit base material 32, which is formed from a plurality of threads oryarn segments, indicated generally at 31 in FIG. 3. The knit basematerial 32 may be knit from a low melt yarn in a single jersey circularknitting process on a circular knitting machine. The knit base material32 has a plurality of courses (which are rows of loops of stitches whichrun across the knit fabric), five of which are shown and designated bythe reference numerals 40, 42, 44, 46, and 48, and a plurality of wales(which are vertical chains of loops in the longitudinal direction of theknit fabric), three of which are shown and designated by the referencenumerals 50, 52, and 54. The respective courses 40, 42, 44, 46, and 48are knitted sequentially from the lowest course number to the highestcourse number.

It will be appreciated that if the knit base material 32 is designed toinclude a low melt component, the threads or yarn segments 31 of theknit base material 32 may each be made of a low melt yarn, oralternatively, only a portion of the threads 31 of the knit basematerial 32, such as alternating threads 31, can be made of a low meltyarn, depending on the desired end use application of the pile side-intubular knit fabric 30.

By way of example, the construction of the portion of the pile side-intubular sliver knit segment 30 in the area of the course 46 and the wale52 will be discussed herein. A loop 56 formed in a yarn segment,indicated at 58, is located in this area, with a loop 60 formed in ayarn segment indicated at 62 being located in the course 44 below theloop 56, and a loop 64 formed in a yarn segment indicated at 66 beinglocated in the course 48 above the loop 56. The loop 56 extends throughthe loop 60 from the outside to the inside of the tubular sliver knitsegment 30 (shown in FIG. 3), and the loop 64 also extends through theloop 56 from the outside to the inside.

A tuft of pile fibers 34 having a loop portion 68 and opposite endportions 70 and 72 is knitted into the knit base material 32 togetherwith the loop 56. The loop portion 68 of that particular tuft of pilefibers 34 is located adjacent the top of the loop 56, and the oppositeend portions 70 and 72 of that particular tuft of pile fibers 34 extendoutwardly from the interior of the loop 56, above the loop 60 and belowthe loop 64. In a similar manner, each of the other tufts of the pilefibers 34 is knitted into the knit base material 32 with a differentloop.

Whether or not the knit base material 32 comprises a low melt material,the tufts of the pile fibers 34 of the tubular sliver knit segment 30can be made of a low melt yarn so that the loop portions thereof may bemelted together, as described in more detail below. In order to providethe pile side-in tubular sliver knit segment 30 with a consistent anduniform pile surface (for use as a paint roller cover), the tufts ofpile fibers 34 including the low melt yarn component can be knitted intothe knit base material 32 in any number of patterns or configurations.For example, every other tuft of pile fibers may be constructed of a lowmelt yarn, so that a repeating pattern of low melt fibers and high meltfibers/yarns are incorporated into the pile 34. The number of tufts oflow melt pile fibers can be determined by a number of factors, includingbut not limited to, the paint roller fabric application, the type of lowmelt and high melt fibers used in both the knit base material 32 and thepile 34, and as a matter of design choice.

Referring now to FIG. 4, a segment of tubular cut pile knit segment 80that may be continuously knitted in an extended length is schematicallyshown. The tubular cut pile knit segment 80 consists of a knit backingor base material 82 having cut pile yarn segments 84 extending from theknit base material 82 on the inner surface of the tubular cut pile knitsegment 80. The knit base material 82 can be made, at least in part,from a low melt yarn that will be discussed below. In certainembodiments of the present invention, the cut pile yarn segments 84 canalso be made, at least in part, from a low melt yarn. It will beappreciated that the tubular cut pile knit segment 80 is manufactured ina pile side-in configuration, in a tubular form similar to the pileside-in tubular segment 30 shown in FIGS. 1 and 2.

The foundation of the tubular cut pile knit segment 80 is the knit basematerial 82, which is formed from a plurality of threads or yarnsegments, indicated generally at 81 in FIG. 4. The knit base material 82may be knit from a low melt yarn in a single jersey circular knittingprocess on a circular knitting machine, as described above. The knitbase material 82 has a plurality of courses (which are rows of loops ofstitches which run across the knit fabric), five of which are shown anddesignated by the reference numerals 90, 92, 94, 96, and 98, and aplurality of wales (which are vertical chains of loops in thelongitudinal direction of the knit fabric), three of which are shown anddesignated by the reference numerals 100, 102, and 104. The respectivecourses 90, 92, 94, 96, and 98 are knitted sequentially from the lowestcourse number to the highest course number.

It will be appreciated that if the knit base material 82 is designed toinclude a low melt component, the threads or yarn segments 81 of theknit base material 82 may each be made of a low melt yarn, oralternatively, a portion, such as alternating threads 81, can be made ofa low melt yarn, depending on the desired end use application of thetubular cut pile knit segment 80.

By way of example, the construction of the portion of the tubular cutpile knit segment 80 in the area of the course 96 and the wale 102 willbe discussed herein. A backing loop 106 formed in a backing yarn segmentindicated at 108 is located in this area, with a backing loop 110 formedin a backing yarn segment indicated at 112 being located in the course94 below the backing loop 106, and a backing loop 114 formed in abacking yarn segment indicated at 116 being located in the course 98above the backing loop 106. The backing loop 106 extends through thebacking loop 110 from the outside to the inside of the tubular cut pileknit segment 80 (shown in FIG. 4), and the backing loop 114 also extendsthrough the backing loop 106 from the outside to the inside. It will atonce be appreciated by those skilled in the art that this arrangement ofbacking loops in sequentially knitted courses is completely opposite tothe way in which knit fabrics have been knitted on known circularknitting machines.

A cut pile yarn segment 84 having a pile loop portion 118 and oppositepile ends 120 and 122 is knitted into the knit base material 82 togetherwith the backing loop 106. The pile loop portion 118 of that particularcut pile yarn segment 84 is located adjacent the top of the backing loop106, and the opposite pile ends 120 and 122 of that particular cut pileyarn segment 84 extend outwardly from the interior of the backing loop106, above the backing loop 110 and below the backing loop 114. In asimilar manner, each of the other cut pile yarn segments 84 is knittedinto the knit base material 82 with a different backing loop.

Whether or not the knit base material 82 comprises a low melt material,the cut pile yarn segments 84 of the pile side-in tubular cut pile knitsegment 80 can be made from a low melt yarn so that the pile loopportions thereof may be melted together with the backing material, asdescribed in more detail below. In order to provide the tubular cut pileknit segment 80 with a consistent and uniform pile surface (for use as apaint roller cover), the cut pile yarn segments 84 including the lowmelt yarn component can be knitted into the knit base material 82 in anynumber of patterns or configurations. For example, alternating the cutpile yarn segments knitted into the knit base material 82 may beconstructed of a low melt yarn, so that a substantially repeatingpattern of low melt cut yarns and high melt yarns are incorporated intothe pile 84. The number of low melt cut pile yarn segments 84incorporated into the knit base material 84 can be determined by anumber of factors, including but not limited to, the paint roller fabricapplication, the type of low melt and high melt fibers used in both theknit base material 82 and the pile 84, and as a matter of design choice.

Turning now to FIG. 5, a segment of pile side-in tubular knit segment300 comprising a combination of tufts of pile fibers 304A and cut pileyarn segments 304B that may be continuously knitted in an extendedlength is schematically shown. The tubular knit segment 300 consists ofa knit backing or base material 302 having pile fibers 304A and 304B,extending from the knit base material 302 on the inner surface of thetubular knit segment 300. The knit base material 302 and the pile fibers304A and 304B are constructed at least in part from a low melt yarn thatwill be discussed below. It will be appreciated that the tubular knitsegment 300 is manufactured in a pile side-in configuration, in atubular form similar to the pile side-in tubular segment 30 shown inFIGS. 1 and 2.

Those skilled in the art will at once realize that while the pile fibers304A and 304B shown in FIG. 5 include only a few fibers each for addedclarity and understanding of the construction of the pile fabric 300,the pile fibers 304A and 304B in the tubular knit segment 300 willactually include sufficient pile fibers 304A and 304B to make a pilethat is sufficiently dense for the intended use of the tubular knitsegment 300 in the manufacture of a paint roller cover.

The foundation of the tubular knit segment 300 is the knit base material302, which is formed from a plurality of threads or yarn segments, asindicated generally at 310. The knit base material 302 may be knit froma low melt yarn in a single jersey circular knitting process on acircular knitting machine, as described in more detail above. The knitbase material 302 has a plurality of courses (which are rows of loops ofstitches which run across the knit fabric), five of which are shown anddesignated by the reference numerals 340, 342, 344, 346, and 348, and aplurality of wales (which are vertical chains of loops in thelongitudinal direction of the knit fabric), three of which are shown anddesignated by the reference numerals 350, 352, and 354. The respectivecourses 340, 342, 344, 346, and 348 are knitted sequentially from thelowest course number to the highest course number.

If it is desired to include a low melt component in the knit basematerial 302, it will be appreciated that all of the threads 310 of theknit base material 302 may be made of a low melt yarn, or alternatively,a portion of knit base material 302, such as alternating threads 310,can be made of a low melt yarn, depending on the desired end useapplication of the tubular knit fabric 300.

As will be appreciated by those skilled in the art, the construction ofthe portion of the tubular knit segment 300 is similar to that describedwith respect to the tubular sliver knit fabric 30 and the tubular cutpile knit segment 80. However, the tubular knit segment 300 includesalternating rows of tufts of pile fibers 304A and cut pile yarn segments304B knitted into the knit base material 302. Each of the tufts of pilefibers 304A have a loop portion 312 and opposite end portions 314 and316, and each of the cut pile yarn segments 304B have a pile loopportion 318 and opposite pile ends 320 and 322.

Whether or not the knit base material 302 comprises a low melt material,the tufts of the pile fibers 304A and/or the cut pile yarn segments 304Bof the tubular sliver knit segment 300 can be made from a low melt yarnso that the loop portions thereof may be melted together with thebacking material, as described in more detail below. In order to providethe tubular knit segment 300 with a consistent and uniform pile surface(for use as a paint roller cover), the pile fibers 304A and 304Bincluding the low melt yarn component can be knitted into the knit basematerial 302 in any number of patterns or configurations. For example,each of the rows of cut pile yarn segments 304B may be constructed of alow melt yarn, while the rows of tufts of pile fibers 304A areconstructed of a high melt, or higher melt material, so that a repeatingpattern of low melt fibers and high melt fibers/yarns are incorporatedinto the pile 304 (including 304A and 304B). Alternatively, tufts ofpile fibers, such as tufts 354 and 356 can be constructed of low meltyarn and/or cut yarn segments 358 and 360 can be constructed of low meltyarn. The number of low melt pile fibers can be determined by a numberof factors, including but not limited to, the paint roller fabricapplication, the type of low melt and high melt fibers used in the knitbase material 302 and/or the pile 304A and 304B, and as a matter ofdesign choice.

Referring now to FIGS. 6 through 11, a number of different bicomponentfibers are shown by way of example (although numerous alternatives maybe manufactured by yarn producers), any of which could be used for thethreads of the knit base material and/or pile fibers of the tubular knitfabrics 30, 80 and 300 of the present invention. Referring first to FIG.6, a sheath-core bicomponent fiber 130 is illustrated which has a highmelt component 132 located in the center of the sheath-core bicomponentfiber 130 and a low melt component 134 located on the outer portion ofthe sheath-core bicomponent fiber 130 which low melt component 134surrounds the high melt component 132. The segments of the low meltcomponent 134 and the high melt component 132 are concentric.

Consistent with the broader aspects of the present invention, a low meltyarn can be provided wherein the low melt component is provided in thecenter of a sheath-core bicomponent fiber with a non-melt or high meltcomponent surrounding the low melt component (a construction opposite tothat shown in FIG. 6). Indeed, any of the described yarn constructionsrecited with respect to FIGS. 6 through 11 can be constructed in amanner in which the low melt component 134 is exchanged in positionwithin the bicomponent fiber. As will be appreciated, the application ofheat, as described in more detail below, will permit the low meltcomponent 132 to melt or otherwise soften or flow together. As such,such oppositely formed bicomponent fibers can be used with good effectin the methods of the present invention.

The particular low melt components 134 and high melt components 132 usedin the tubular knitted fabric of the present invention can be anymaterial known to those skilled in the art, provided that the low meltcomponent melts at temperature sufficiently below the melting point ofthe high melt component so as not to damage the high melt component 132during the manufacturing process. Such low melt components/yarns caninclude, but are not limited to, low-melting thermoplastic polymer orcopolymer, such as polypropylene, polyethylene, low melt polyester, lowmelt co-polyamide (nylon) and the like having a known and/orpredetermined melting point. The high melt component 134 is selected soas to remain unaffected at the low melting point of the low meltcomponent and can be constructed of any natural fiber, thermoplasticpolymer/copolymer or a composite thereof.

Consistent with the broader aspects of the present invention, the term“low melt yarn” can encompass yarns comprising at least one low meltfilament or strand, as described above, and also including a pluralityof additional high melt or non-low melt filaments or strands that arecombined together by methods well known to those skilled in the art. Theadditional high melt/non-low melt filaments or strands may be comprisedof any suitable natural or synthetic fiber suitable for combination withthe low melt fiber or strand. Suitable materials include but are notlimited to nylon, rayon, polypropylene, polyester, polyester-cottonblends, cotton, wool and acrylic. Other materials may be used so long asthey are compatible with the selected low melt yarn and the finalapplication of the tubular knitted pile fabric segment. In this way, thepresent invention is not limited to low melt yarns having only twocomponents and includes low melt yarns having multiple strandcomponents.

It will be appreciated that the ratio of low melt component to high meltcomponent used in a particular low melt yarn encompassed by the presentinvention, will vary depending on the particular end use application ofthe tubular knitted pile fabric segment. Where a more rigid integralcore is to be formed, a low melt yarn having a low melt fiber or strandcomposition that is substantially equal to or greater than the high meltcomponent composition can be used. For applications where the integralcore of the tubular knitted pile fabric segment may be furtherreinforced, a low melt fiber or strand composition that is less than thehigh melt component composition can be used.

As will further be appreciated, the low melt component 134 can beselected to have a predetermined shrinkage rate and/or known contractionproperties when heated or melted. In particular, the low melt component,specifically a thermoplastic component as described above, will have aknown/predetermined percent (%) shrinkage rate or value, as will be wellknown to those skilled in the art. For a specific bicomponent or lowmelt yarn, such a value or rate will depend on the type of low meltfiber selected, the number of thermoplastic fibers used in a given yarn,any pretreatment of the yarn prior to knitting the tubular fabricsegment and can be a matter of design choice. Such a percent shrinkagevalue can range from approximately 1% to over about 30%, depending onthe low melt yarn design.

The linear mass density of the backing yarn, the pile fibers and/or cutyarn segments used by the present invention may vary betweenapproximately 150 denier and approximately 1500 denier, with a preferredlinear mass density being between approximately 560 denier andapproximately 1200 denier. It will be understood, however, that thelinear mass density of each fiber or strand of the bicomponent ormulti-component low melt yarn will be determined by the specificfiber/strand selected, and is a matter of design choice, depending atleast in part on the knitting equipment utilized and the end useapplication of the tubular knitted pile fabric segment.

Referring next to FIG. 7, a side-by-side bicomponent fiber 140 isillustrated which has one side (a semicircular cross section) made of ahigh melt component 142 and the other side (a complementary semicircularcross section) made of a low melt component 144. Referring now to FIG.8, an eccentric sheath-core bicomponent fiber 150 is illustrated whichhas a high melt component 152 located in the center of the eccentricsheath-core bicomponent fiber 150 and a low melt component 154 locatedon the outer portion of the eccentric sheath-core bicomponent fiber 150which low melt component 154 surrounds the high melt material 152. Bydefinition in an eccentric sheath-core relationship, the segments of thelow melt component 154 and the high melt component 152 are notconcentric.

Referring next to FIG. 9, a matrix-fibril bicomponent fiber 160 isillustrated which has four segments of high melt component 162distributed in a matrix of low melt component 164 that entirelysurrounds the segments of high melt component 162. Although foursegments of high melt component 162 are shown in FIG. 9, more or fewercould be used. Also, although the four segments of high melt component162 are shown as being evenly distributed in the surrounding low meltcomponent 164, the segments of high melt component 162 could bedistributed more randomly in the surrounding low melt component 164 aswell.

Referring now to FIG. 10, a segmented pie bicomponent fiber 170 isillustrated which has eight pie-shaped segments that are evenlydistributed around the circumference of the segmented pie bicomponentfiber 170. The segments alternate between high components 172 and lowmelt components 174. Although four segments of high melt component 172and four segments of low melt component 174 are shown in FIG. 10, moreor fewer could be used.

Referring next to FIG. 11, a bicomponent yarn 180 is illustrated whichis made up of four fibers, two of which are high melt fibers 182 and twoof which are low melt fibers 184. As is the case with any yarn, the highmelt fibers 182 and the low melt fibers 184 are twisted together to formthe segment of bicomponent yarn 180. Although two high melt fibers 182and two low melt fibers 184 are shown in FIG. 11, more or fewer of eachcould be used.

Referring now to FIGS. 12 and 13, a mandrel heating assembly 190 isillustrated in two cross sectional views. The mandrel heating assembly190 of the exemplary embodiment has a mandrel 192 that is cylindricaland has an outer diameter of approximately one and three-eighths inches(35 millimeters) or slightly less and has a coaxial cylindrical aperture194 located therein that is approximately three-quarters of an inch (19millimeters) in diameter or slightly larger extending therethrough,which mandrel 192 may be made out of steel. A smaller aperture 196 thatis approximately one-eighth of an inch (3.2 millimeters) in diameter orslightly larger extends longitudinally through the mandrel 192 and islocated in the mandrel 192 between the aperture 194 and the outersurface of the mandrel 192.

A cartridge heater 198 is located in the aperture 194 in the mandrel192. The cartridge heater 198 may be a Watlow FIREROD Part No.N24A23-E12H cartridge heater from Watlow Electric Manufacturing Companyof St. Louis, Mo. The cartridge heater 198 has a three-quarter inch (19millimeter) diameter and is twenty-four inches (610 millimeters) long,has a 2750 Watt rating, and has two heater leads 200 extending from oneend thereof.

A thermocouple 202 is located in the aperture 196 in the mandrel 192.The thermocouple 202 may be an Omega Model No. JMQSS-125G-6 thermocouplefrom Omega Engineering, Inc. of Stamford, Conn. The thermocouple 202 hasa has an one-eighth inch (3.2 millimeter) diameter, is twenty-fourinches (610 millimeters) long, and has two thermocouple leads 204extending from one end thereof.

Referring next to FIG. 14, a control circuit for operating the cartridgeheater 198 based on temperature information received from thethermocouple 202 is illustrated. A Eurotherm Model No. 2216e generalpurpose PID (Proportional-Integral-Derivative) temperature controllerfrom Eurotherm Inc. of Leesburg, Va. has as an input the thermocoupleleads 204 from the thermocouple 202, and is connected through the heaterleads 200 to operate the cartridge heater 198 at the desiredtemperature.

Turning now to FIG. 15, a tubular knitted pile fabric 220 (which may bethe tubular sliver knit segment 30, the tubular cut pile knit segment 80or the tubular knit pile fabric 300 having a combination of sliver fiberand cut yarn pile) has a first end 222 and a second end 224 and is shownas it being inverted. The pile side-in segment (30, 80 or 300) isinverted to a pile side-out configuration so that the pile 34 is on theoutside surface thereof, and the knit base 32 is on the inside surfacethereof. The tubular knitted pile fabric 220 can be inverted by anymeans known to those skilled in the art, including, but not limited tomanually, or using a an automated transfer tube process.

As best illustrated in FIGS. 16 and 17, the inverted tubular knittedpile fabric 220 may become stretched or otherwise wrinkled during theinversion process. In particular, the tubular knitted pile fabric 220can have an irregular inner diameter 221 and outer diameter 223 alongits entire length 225 after the segment is inverted from a pile side-into a pile side-out configuration. It will also be understood that theinverted tubular knitted pile fabric 220 may also be deformed as to itslength 225, depending on the type of inversion process used. Inparticular, the length 225 of the inverted tubular knitted pile fabric220 may be longer than that desired.

Referring next to FIG. 18, the inverted, pile side-out tubular knittedpile fabric 220 is shown as it is about to be pulled onto the exteriorsurface of a hollow cylindrical aluminum heating tube 226 having a firstend 228 and a second end 230 and a nonstick substance 232 on the outersurface thereof. The aluminum heating tube 226 has an outer diameter 233that is approximately the same as the inner diameter of a finished paintroller cover core (paint roller cover cores typically have an innerdiameter of approximately one and one-half inches (38 millimeters),although alternative sizes such as inner diameters of one andthree-quarters inches (44 millimeters) and two inches (51 millimeters)can be manufactured as well).

The aluminum heating tube 226 has an inner diameter of approximately oneand three-eighths inches (35 millimeters) or slightly greater and issized to fit removably over the mandrel 192 of the mandrel heatingassembly 190 (shown in FIGS. 12 and 13). (It should be noted that theinner diameter of the aluminum heating tube 226 is not critical, andindeed will vary according to the outer diameter of the mandrel 192 ofthe mandrel heating assembly 190.) The outer surface of the aluminumheating tube 226 is coated with a low coefficient of friction materialsuch as silicone or polytetrafluoroethylene (PTFE, such as the materialmarketed by DuPont under the trademark TEFLON) to provide a non-sticksubstance 232 thereupon.

As best illustrated in FIGS. 19 and 20, the inner diameter 221 of thepile side-out tubular knitted pile fabric 220 may be larger than theouter diameter of the aluminum heating tube 226, and/or may be generallyinconsistent in diametral dimension along its length 225 (as shown inFIGS. 16 and 17).

The tubular knitted pile fabric 220 is of a length that corresponds tothe desired length of a paint roller cover, taking into account theshrinkage rate of the low melt yarn used therein. For a nine inch (229millimeters) long paint roller cover, the tubular knitted pile fabric220 will have to be sufficiently long such that following theapplication of heat the resulting paint roller cover will be of thedesired length. For example, if the low melt yarn utilized is known toresult in an approximately eight percent shrinkage rate, the tubularknitted pile fabric 220 will need to be approximately 9.8 inches (249millimeters) long.

It will be appreciated by those skilled in the art that the tubularknitted pile fabric 220 could alternately be sized for use inmanufacturing a plurality of paint roller covers of any of severaldifferent lengths. For example, the tubular knitted pile fabric 220could be approximately one hundred inches (2.54 meters) long, which is asufficient length to allow it to be used for the manufacture of sevennine inch (229 millimeter) long paint roller covers. In this case, ofcourse, the aluminum heating tube 226 and the mandrel heating assembly190 (shown in FIGS. 13 and 14) would have to be proportionately longeras well.

In FIG. 18, the tubular knitted pile fabric 220 is shown with its secondend 224 about to be pulled over the first end 228 of the aluminumheating tube 226. FIG. 19 shows the tubular knitted pile fabric 220partly pulled onto the aluminum heating tube 226, and FIG. 20 shows thetubular knitted pile fabric 220 fully pulled onto the aluminum heatingtube 226, with the second end 224 of the tubular knitted pile fabric 220located close adjacent to the second end 230 of the aluminum heatingtube 226. The tubular knitted pile fabric 220 fits easily on the outerdiameter of the aluminum heating tube 226, and is not stretched on thealuminum heating tube 226.

Referring next to FIG. 21, the aluminum heating tube 226 with thetubular knitted pile fabric 220 located thereupon is about to be placedonto the mandrel heating assembly 190. As mentioned above, the insidediameter of the aluminum heating tube 226 is sized to fit removably overthe outer diameter of the mandrel 192 of the mandrel heating assembly190, but with a relatively close fit to allow heat from the mandrelheating assembly 190 to be transferred to and through the aluminumheating tube 226. Prior to placing 226 with the tubular knitted pilefabric 220 located thereupon over the mandrel heating assembly 190, themandrel heating assembly 190 is brought up to the desired temperature.Typically, this will take less than one minute.

The temperature of the mandrel heating assembly 190 is a function ofwhich particular bicomponent material is used in the low melt yarn usedfor the backing and pile of the tubular knitted pile fabric 220. Morespecifically, the temperature used must be at or above the melting pointof the low melt component used in the backing and pile materials, butbelow the melting point of the high melt component used in the backingand pile material of the tubular knitted pile fabric 220. Thetemperature of the mandrel heating assembly 190 accordingly variesaccording to the properties of the bicomponent material, and willtypically be set between approximately 250 degrees Fahrenheit (121degrees Celsius) and approximately 450 degrees Fahrenheit (232 degreesCelsius), although with some bicomponent materials the temperature mayvary from as low as approximately 250 degrees Fahrenheit (121 degreesCelsius) to as high as 600 degrees Fahrenheit (316 degrees Celsius).

In FIG. 21, the aluminum heating tube 226 with the tubular knitted pilefabric 220 located thereupon is shown with the second end 230 of thealuminum heating tube 226 about to be pulled over the mandrel heatingassembly 190. FIG. 22 shows the aluminum heating tube 226 with thetubular knitted pile fabric 220 located thereupon fully pulled onto themandrel heating assembly 190, where it is heated and maintained for aperiod of time sufficient to activate the backing yarn and knit/loopedends of the low melt pile fibers. (Activating the backing yarn andlooped/knit ends of the pile fibers constitutes melting the low meltcomponent of the bicomponent material of the backing and pile yarn ofthe tubular knitted pile fabric 220 so that it will flow together tolock the backing yarn and knit looped portions of the pile fibers intoan integral cylindrical core 246 around the aluminum heating tube 226.)

This period of time can vary between approximately five seconds toapproximately ninety seconds, with typical times for most bicomponentmaterials varying from approximately five seconds to approximately sixtyseconds.

As best illustrated in FIGS. 22 and 23, during this activation process,the low melt component 132 of each of the backing yarn and looped/knitends of the pile fibers will shrink according to the shrinkrate/thermoplastic properties of the low melt components utilizedtherein. In particular, the backing yarn and/or looped end of the pileis designed to shrink a sufficient amount so that the inner diameter 221of the tubular knitted pile fabric 220 closely conforms to the outersurface 232 of the aluminum heating tube 226, thereby shrinking to theapproximate size of the outer diameter 233 of the aluminum heating tube226, as illustrated in FIG. 23.

Clamps securing the fabric in place (not shown herein) can be utilizedto control the fabric's shrinking characteristics. Following theactivation process, the aluminum heating tube 226 with the now-activatedtubular knitted pile fabric 240 located thereupon is removed from themandrel heating assembly 190 and allowed to cool, which typically takesonly a few seconds. The activated tubular knitted pile fabric 240 maythen be removed from the aluminum heating tube 226.

Referring next to FIG. 23, the activated tubular knitted pile fabric 240is shown as having a first end 242 and a second end 244, with a pile 248extending outwardly from the activated tubular knitted pile fabric 240.The inside of the activated tubular knitted pile fabric 240 is acylindrical fused backing, comprising a substantially rigid integralcore member 246. Finishing the activated tubular knitted pile fabric 240will include the steps of combing the pile 248 of the activated tubularknitted pile fabric 240 and shearing it to the desired length. Finally,the ends 242 and 244 of the activated tubular knitted pile fabric 240may be finished and the edges of the activated tubular knitted pilefabric 240 may be beveled, and any loose fibers may be vacuumed off.

While the exemplary embodiment discussed above produces a nine inch (229millimeter) paint roller cover, the tubular knitted pile fabric 220, thealuminum heating tube 226, and the mandrel heating assembly 190 (asshown in FIGS. 21 and 22) could alternately be sized for use inmanufacturing a plurality of paint roller covers of any of severaldifferent lengths. For example, a substantially longer activated tubularknitted pile fabric 240 could be produced and subsequently be cut intounfinished paint roller cover segments of any desired size. Theseunfinished paint roller cover segments would then be finished asdescribed above.

An alternate embodiment of the paint roller cover manufacturing methodof the present invention is shown in FIGS. 24 through 28. Referringfirst to FIG. 24, one or more layers of dry adhesive film 250 is woundaround the aluminum heating tube 226. The dry adhesive film 250generally consists of a thin plastic film that is coated on one side(the side that will be wound facing outwardly) with a non-tackyadhesive, and may optionally have a pressure-sensitive adhesive on theopposite side to facilitate the installation of the dry adhesive film250 onto the aluminum heating tube 226. One dry adhesive film that maybe used, for example, is Stock No. 233 from Lenderink Technologies inBelmont, Mich. The thickness of the dry adhesive film 250 may vary fromapproximately 0.0005 inches (0.0127 millimeters) thick to approximately0.01 inches (0.254 millimeters) thick. For example, from one to sevenlayers of 0.0012 inch (0.0305 millimeter) thick dry adhesive film 250,or from one to three layers of thicker dry adhesive film 250 (0.0024inch (0.61 millimeter) thick to 0.0072 inch (0.183 millimeter) thick)being used. The dry adhesive film 250 is cut when a sufficient length ofthe dry adhesive film 250 has been wound around the aluminum heatingtube 226 to form a wrapped dry adhesive film 252, as shown in FIG. 25.

Referring next to FIG. 26, the tubular knitted pile fabric 220 is shownwith its second end 224 about to be pulled over the first end 228 of thealuminum heating tube 226, and then onto the wrapped dry adhesive film252 on the aluminum heating tube 226 FIG. 27 shows the tubular knittedpile fabric 220 fully pulled onto the wrapped dry adhesive film 252 onthe aluminum heating tube 226, with the aluminum heating tube 226 withthe tubular knitted pile fabric 220 and the wrapped dry adhesive film252 located thereupon about to be placed over the mandrel heatingassembly 190.

FIG. 28 shows the aluminum heating tube 226 with the tubular knittedpile fabric 220 and the wrapped dry adhesive film 252 located thereuponfully pulled onto the mandrel heating assembly 190, where it is heatedand maintained for a period of time sufficient to activate the wrappeddry adhesive film 252 and the backing yarn/looped ends of the low meltpile fiber, with the wrapped dry adhesive film 252 and the low meltcomponent of the bicomponent material of the backing yarn and loopedends of pile fiber of the tubular knitted pile fabric 220 flowingtogether and shrinking a sufficient amount to form an integralcylindrical core around the mandrel 192 of the mandrel heating assembly190. Following the activation process, the aluminum heating tube 226with the now-fused together material is removed from the mandrel heatingassembly 190 and allowed to cool. The resulting assembly may then beremoved from the aluminum heating tube 226 and finished as describedabove.

Referring finally to FIG. 29, the paint roller cover manufacturingmethod of the present invention is shown in a flow chart that includes anumber of the variations discussed herein. The paint roller covermanufacturing operation starts in a manufacture tubular knitted pilefabric sleeve step 260 in which the tubular knitted pile fabric used inthe tubular knitted pile fabric 220 (shown in FIGS. 16 through 20) ismanufactured.

The tubular knitted pile fabric used in the tubular knitted pile fabric220 (shown in FIGS. 18 through 23) is represented in a manufacture pileside-in tubular sliver knit fabric sleeve 260A, which corresponds tomanufacture of the tubular sliver knit segment 30 shown in FIGS. 1through 3. The tubular knitted pile fabric used in the tubular knittedpile fabric 220 can also be a tubular cut pile knit fabric sleeve 260B,which corresponds to manufacture of the pile side-in tubular cut pileknit segment 80 shown in FIGS. 1, 2 and 4. The tubular knitted pilefabric used in the tubular knitted pile fabric 220 can also be a pileside-in tubular knit fabric sleeve 260C including tufts of pile fibersand cut pile yarn segments, which correspond to manufacture of thetubular knit segment 300 shown in FIGS. 1, 2 and 5.

The process next moves to a cut tubular knitted pile fabric sleeve tolength step 262 in which the tubular knitted pile fabric is cut to thedesired length of the tubular knitted pile fabric 220. As mentionedabove, the tubular knitted pile fabric 220 will have to be sufficientlylong such that following the application of heat the resulting paintroller cover will be of the desired length, taking account of theshrinkage rate of the low melt yarn used therein that may occur duringthe heating process. Alternately, the tubular knitted pile fabric 220could be sized for use in manufacturing a plurality of paint rollercovers of any of several different lengths. For example, a substantiallylonger activated tubular knitted pile fabric 240 (shown in FIG. 23)could be produced and subsequently be cut into unfinished paint rollercover segments of any desired size.

The process next moves to an inversion step 263, wherein the pileside-in tubular knitted pile fabric sleeve is inverted from a pileside-in configuration to a pile side-out configuration. This inversionoperation may be accomplished by any means known to those skilled in theart.

Optionally, an apply dry adhesive film to aluminum heating tube step 264can then be used if it is desired to apply the wrapped dry adhesive film252 (shown in FIG. 25) under the tubular knitted pile fabric 220 on thealuminum heating tube 226.

With or without the apply dry adhesive film to aluminum heating tubestep 264, the tubular knitted pile fabric 220 is placed onto thealuminum heating tube 226 in a place tubular knitted pile fabric sleeveon aluminum tube step 266, as shown in FIGS. 18 through 20 (without thewrapped dry adhesive film 252) or in FIG. 26 (with the wrapped dryadhesive film 252). The process next moves to a preheat mandrel todesired temperature step 268, wherein the mandrel heating assembly 190is heated to the desired temperature to activate the low melt componentin the backing of the tubular knitted pile fabric 220.

The process then moves to a place aluminum heating tube with fabricsleeve onto mandrel step 270, in which the aluminum heating tube 226with the tubular knitted pile fabric 220 (and, optionally, the wrappeddry adhesive film 252) located thereupon is placed onto the mandrelheating assembly 190 to initiate the heating process, as shown in FIG.22. The aluminum heating tube 226 with the tubular knitted pile fabric220 (and, optionally, the wrapped dry adhesive film 252) locatedthereupon is heated on the mandrel heating assembly 190 for apredetermined time as shown in FIG. 22 in a heat fabric sleeve onmandrel for a predetermined time step 272.

The process then moves to a remove aluminum tube with activated fabricsleeve from mandrel step 274 in which the aluminum heating tube 226 withthe activated tubular knitted pile fabric 240 (shown in FIG. 23) isremoved from the mandrel heating assembly 190 and allowed to cool. Atthis point, the activated tubular knitted pile fabric 240 has cooled andhas an integral cylindrical fused core 246 located on the insidethereof, as indicated in a fabric sleeve has formed integral core memberstep 276.

Optionally, an apply liquid adhesive layer to integrally formed coremember of tubular fabric sleeve step 277 can then be used if it isdesired to further enhance the rigidity of the integrally formed coremember 246 of tubular fabric sleeve 240.

Next, in an optional cut fabric-covered core member to desired lengthsstep 278, the activated tubular knitted pile fabric 240 may be cut intoa plurality of unfinished paint roller covers of any desired size. Thisstep is, of course, not performed if the tubular knitted pile fabric 220was cut to meet its finished size in the cut tubular knitted pile fabricsleeve to length step 262. The unfinished paint roller covers may thenhave the fabric pile thereupon combed and sheared to a desired length ina comb and shear fabric pile step 280. It should be noted that the comband shear fabric pile step 280 may instead be performed before the cutfabric-covered core member to desired lengths step 278.

Next, in a bevel edges of paint roller covers step 282, the edges of theunfinished paint roller covers are beveled to finish them. Finally, in avacuum paint roller covers step 284, loose fibers are vacuumed off theunfinished paint roller covers, finishing them into paint roller coverswhich may then be packaged and sold (typically, vacuuming isaccomplished throughout the brushing, shearing, and beveling stepsrather than as a separate step).

It may therefore be appreciated from the above detailed description ofthe preferred embodiment of the present invention that it teaches amethod by which a paint roller cover may be manufactured from tubularknitted pile fabric knitted in a pile side-in manner. In particular, thepile side-in tubular knit fabric for use in the methods of the presentinvention can be knitted on conventional tubular knitting machines.Further, in practicing the paint roller cover manufacturing method ofthe present invention, use of a low melt yarn or fiber in one of thebacking material and/or pile in the manufacture of a pile side-intubular fabric, inverting the fabric and then heating the low meltmaterial to its melting and/or shrinking point ensures that the finalpaint roller cover is free from wrinkles or other surface defects thatcan be introduced into the tubular knitted pile fabric during theinverting process.

The paint roller cover manufacturing method of the present inventionresults in an acceptable pile which extends from an acceptably rigidcore which can be installed on and used with any conventional paintroller frame, or on a frame uniquely designed for the paint rollerutilizing the new core design. The paint roller cover manufacturingmethod of the present invention facilitates either the manufacture of apaint roller cover of a desired finished length, or the manufacture ofan extended length segment from which segments of any desired size canbe cut for finishing as paint roller covers, thereby facilitating themass manufacture of paint roller covers. The paint roller covermanufacturing method of the present invention can use tubular knittedpile fabric including sliver fibers, cut yarn pile or a combination ofeach, as well as utilize a number of different backing materials.

The paint roller cover manufacturing method of the present inventionresults in a construction which is both durable and long lasting, andyields a paint roller cover of superior quality. The paint roller covermanufacturing method of the present invention also reduces the cost ofmanufacturing paint roller covers when compared to conventional methodsof manufacturing paint roller covers by manufacturing paint rollerswithout using a separately provided core member, thereby affording itthe broadest possible market. Finally, all of the aforesaid advantagesand aspirations of the paint roller cover manufacturing method of thepresent invention are achieved without incurring any substantialrelative disadvantage.

Although the foregoing description of the paint roller covermanufacturing method of the present invention has been shown anddescribed with reference to particular embodiments and applicationsthereof, it has been presented for purposes of illustration anddescription and is not intended to be exhaustive or to limit theinvention to the particular embodiments and applications disclosed. Itwill be apparent to those having ordinary skill in the art that a numberof changes, modifications, variations, or alterations to the inventionas described herein may be made, none of which depart from the spirit orscope of the present invention. The particular embodiments andapplications were chosen and described to provide the best illustrationof the principles of the invention and its practical application tothereby enable one of ordinary skill in the art to utilize the inventionin various embodiments and with various modifications as are suited tothe particular use contemplated. All such changes, modifications,variations, and alterations should therefore be seen as being within thescope of the present invention as determined by the appended claims wheninterpreted in accordance with the breadth to which they are fairly,legally, and equitably entitled.

1. A method of manufacturing a paint roller cover, comprising: providing a tubular knitted pile fabric sleeve having a first end and a second end, said tubular knitted pile fabric sleeve comprising: a base fabric being knitted from a base strand and having a tubular configuration defining an outside and an inside; and pile strands knitted into said base fabric and extending inwardly from said base fabric to form the pile of said tubular knitted pile fabric sleeve; wherein at least one of said base strand and said pile strands is made at least in part from a first material and a second material, wherein said first material has a lower melting point than said second material and wherein the second material has a predetermined shrinkage rate when heated to said lower melting point; inverting a first length of said tubular knitted pile fabric sleeve from a pile side-in configuration to a pile side-out configuration; placing said inverted first length of said tubular knitted pile fabric sleeve onto a cylindrical member having a cylindrical outer surface with said inside of said base fabric in contact with said cylindrical outer surface of said cylindrical member; heating said base fabric to cause at least a portion of said first material to melt and fuse said base fabric together to thereby create a cylindrical integral core member which, when cooled, is sufficiently rigid to preserve its cylindrical configuration and removing said cylindrical integral core member from said cylindrical member.
 2. A method as defined in claim 1, wherein said tubular knitted pile fabric sleeve comprises: a sliver knit tubular knitted pile fabric sleeve wherein said pile strands comprise tufts of sliver fibers.
 3. A method as defined in claim 1, wherein said tubular knitted pile fabric sleeve comprises: a knit tubular knitted cut pile fabric sleeve wherein said pile strands comprise cut pile yarn segments.
 4. A method as defined in claim 1, wherein said tubular knitted pile fabric sleeve comprises: a tubular knitted fabric sleeve wherein said pile strands comprise tufts of sliver fibers and cut pile yarn segments.
 5. A method as defined in claim 1, wherein said base strand and said pile strands comprises at least one bicomponent fiber comprising: a first bicomponent fiber material having a first melting point; and a second bicomponentfiber material having a second melting point that is lower than said first melting point, wherein the second bicomponent fiber material has a predetermined shrinkage rate when heated to said second melting point.
 6. A method as defined in claim 5, wherein said at least one bicomponent fiber is arranged and configured with a sheath made of said second bicomponent fiber material that surrounds a core made of said first bicomponent fiber material.
 7. A method as defined in claim 5, wherein said at least one bicomponent fiber is arranged and configured with a sheath made of said first bicomponent fiber material that surrounds a core made of said second bicomponent fiber material.
 8. A method as defined in claim 5, wherein said at least one bicomponent fiber is arranged and configured with segments of said first and second bicomponent fiber material respectively located in a side-by-side arrangement.
 9. A method as defined in claim 5, wherein said at least one bicomponent fiber is arranged and configured with a plurality of strands made of said first bicomponent fiber material that are surrounded by a sheath made of said second bicomponent fiber material.
 10. A method as defined in claim 5, wherein said first bicomponent fiber material is selected from the group of materials consisting of polyester and polypropylene.
 11. A method as defined in claim 5, wherein said second bicomponent fiber material is selected from the group of materials consisting of polyethylene terephthalate (PET), polyethylene, and copolyester.
 12. A method as defined in claim 1, wherein at least one of said base strand and said pile strands comprises a bicomponent yarn comprising: at least one fiber made of a first material having a first melting point; and at least one fiber made of a second material having a second melting point that is lower than said first melting point.
 13. A method as defined in claim 1, wherein said base strand and said pile strands comprise at least in part a low melt material.
 14. A method as defined in claim 13, wherein said base strand and said pile strands comprise different low melt materials.
 15. A method as defined in claim 1, wherein said wherein said base strand comprises a yarn having a linear mass density of between approximately 150 denier and approximately 1500 denier.
 16. A method as defined in claim 1, wherein said inverted tubular knitted pile fabric sleeve has an inner diameter that is larger than or approximately the same size as the outer diameter of said cylindrical member.
 17. A method as defined in claim 1, wherein said inverted tubular knitted pile fabric sleeve and said cylindrical member are both longer than the length of a paint roller cover.
 18. A method as defined in claim 1, additionally comprising: cutting said integral core member into a plurality of unfinished paint roller covers each covered with knitted pile fabric having pile extending outwardly therefrom and each having edges located at opposite ends thereof.
 19. A method as defined in claim 1, wherein said inverted tubular knitted pile fabric sleeve is of a length that is sufficiently long such that following said heating step said integral core member will be substantially the length needed to produce a paint roller cover of the desired length.
 20. A method as defined in claim 1, wherein said cylindrical member comprises: a hollow cylindrical aluminum heating tube having a non-stick outer surface.
 21. A method as defined in claim 20, wherein said aluminum heating tube has an outer diameter that is substantially identical to a desired inner diameter of a finished paint roller cover.
 22. A method as defined in claim 20, wherein said heating step comprises: placing the aluminum heating tube with the tubular knitted pile fabric sleeve located thereupon onto a preheated mandrel heating assembly; and after a predetermined period of time, removing said aluminum heating tube from said mandrel heating assembly and allowing said integral core member to cool.
 23. A method as defined in claim 22, wherein said mandrel heating assembly is preheated to a temperature that is sufficient to cause said first material to melt and conform to the size of said outer diameter of said aluminum heating tube.
 24. A method as defined in claim 23, wherein said mandrel heating assembly is preheated to a temperature that is less than 650 degrees Fahrenheit (343 degrees Celsius).
 25. A method as defined in claim 23, wherein said mandrel heating assembly is preheated to a temperature that is less than 450 degrees Fahrenheit (232 degrees Celsius).
 26. A method as defined in claim 22, wherein said predetermined time is sufficient time for said first material to melt and fuse said base fabric and looped ends of said pile strands together to cause said first material to melt and conform to the size of said outer diameter of said aluminum heating tube.
 27. A method as defined in claim 26, wherein said predetermined time is between approximately five seconds and approximately ninety seconds.
 28. A method as defined in claim 1, additionally comprising: placing a segment of dry adhesive film onto said cylindrical outer surface of said cylindrical member before said tubular knitted pile fabric sleeve is placed onto said cylindrical member, said tubular knitted pile fabric sleeve thus being located over said segment of dry adhesive film on said cylindrical outer surface of said cylindrical member; wherein said dry adhesive film melts at least in part and fuses with said base fabric.
 29. A method as defined in claim 28, wherein said dry adhesive film is between approximately 0.0005 inches (0.0127 millimeters) and 0.01 inches (0.254 millimeters) thick.
 30. A method as defined in claim 1, additionally comprising: applying a liquid adhesive layer onto said cylindrical integral core member of said tubular knitted pile fabric sleeve and allowing said adhesive layer to dry.
 31. A method as defined in claim 1, wherein said tubular knitted pile fabric sleeve has edges located at said first and second ends thereof, said method additionally comprising: combing said pile of said tubular knitted pile fabric sleeve extending from said integral core member; shearing said pile of said tubular knitted pile fabric sleeve extending from said integral core member to the desired length; beveling said edges of said tubular knitted pile fabric sleeve extending from said integral core member; and vacuuming said pile of said knitted pile fabric extending from said integral core member.
 32. A method as defined in claim 1, additionally comprising: cutting said tubular knitted pile fabric sleeve extending from said integral core member into a plurality of unfinished paint roller covers each of a desired length; combing said pile of said knitted pile fabric on said unfinished paint roller covers; shearing said pile of said knitted pile fabric on said unfinished paint roller covers to the desired length; beveling said edges of said unfinished paint roller covers; and vacuuming said pile of said unfinished paint roller covers.
 33. A method of manufacturing a paint roller cover, comprising: providing a tubular knitted pile fabric sleeve having a first end and a second end, said tubular knitted pile fabric sleeve comprising: a base fabric having a tubular configuration defining an outside and an inside; pile strands knitted into said base fabric and extending inwardly from said base fabric to form the pile of said tubular knitted pile fabric sleeve; wherein at least one of said base fabric and said pile strands comprise bicomponent fiber having a first material and a second material, wherein said first material has a lower melting point than said second material; inverting said tubular knitted pile fabric sleeve from a pile side-in configuration to a pile side-out configuration; preheating a mandrel heating assembly to a temperature that is sufficient to cause said first material to melt; placing the inverted tubular knitted pile fabric sleeve on a heating tube; placing the heating tube with the inverted tubular knitted pile fabric sleeve located thereupon onto the mandrel heating assembly to heat said base fabric to cause at least a portion of said first material to melt and fuse said base fabric and said pile strands together to thereby create a cylindrical integral core member; and removing said heating tube from said mandrel heating assembly and allowing said integral core member to cool, said cylindrical integral core member, when cooled, having sufficient rigidity to preserve its cylindrical configuration.
 34. A method of manufacturing a paint roller cover, comprising: providing a tubular knitted pile fabric sleeve comprising: a tubular base fabric; and extending inwardly pile strands knitted into said base fabric, wherein at least one of said tubular base fabric and said pile strands comprise at least in part a bicomponent fiber; inverting said tubular knitted pile fabric sleeve from a pile side-in configuration to a pile side-out configuration; placing said tubular knitted pile fabric sleeve onto a cylindrical member; heating said base fabric to cause said bicomponent material to melt at least in part and fuse together to thereby create a cylindrical integral core member so that, when cooled, said tubular base fabric remains in a cylindrical configuration; and removing said cylindrical integral core member from said cylindrical member. 